1. Field of the Invention
The present invention relates to an image data processing technique, and it particularly relates to method and apparatus for coding or decoding image data included in a plurality of frames.
2. Description of the Related Art
As the performance of medical image equipment such as MRI and CT system advances and improves significantly in recent years, more and more cross sectional images can be photographed under the same level of X-ray exposure dosage to a patient. For example, many cross sectional medical images of a diseased part can be acquired for as many as 300-1000 images at a time as a result of the recent improvement, compared to 20 images as the maximum in the past
On the other hand, even though such a great number of images can be acquired, those images need be stored for a predetermined period of time as bound by the law, thus causing a trouble in medical institutions because of extremely huge amount of image data to be stored. Moreover, when the medical images need be transmitted within a hospital or between different hospitals, the large number of images results in the unwanted increase of communication time and may threaten the smooth operation of the medical institutions.
In order to cope with the situation, recently the Ministry of Health and Welfare in Japan comes to approve of the storage of the medical images in the form of digital data because digitization makes possible application of the various data compression techniques. However, the current compression technique does not catch up with the increase of highly microscopic image data acquired not only in the medical field but also in the image processing field in general. Therefore, the search for a further efficient compression technique is an everlasting theme in the field, and such technology is highly desired in our advanced society.